SS 2

Revision – First Term

Physics SS 2 First Term

📌 Welcome to Your First Term Revision!

This comprehensive revision covers all the topics from the First Term. Use this to:

Review key concepts from each topic
Practice with revision questions
Prepare for your end-of-term examination
Identify areas that need more attention

Topics Covered in First Term

Week	Topic	Key Concepts
1	Heat and Temperature	Difference between heat and temperature, thermometers, temperature scales (Celsius, Fahrenheit, Kelvin)
2	Thermal Expansion	Expansion of solids, liquids, gases; bimetallic strips; applications and consequences
3	Thermal Conductivity	Conductors and insulators; factors affecting thermal conductivity
4	Gas Laws	Boyle's Law, Charles' Law, Pressure Law; The General Gas Equation
5	Evaporation and Boiling	Differences; factors affecting evaporation; latent heat
6	Structure of Matter	Atomic structure; kinetic theory; states of matter; Brownian motion
7	Work, Energy and Power	Definition of work; forms of energy; conservation of energy; power
8	Simple Machines	Levers, pulleys, inclined planes, screws, wedges; MA, VR, efficiency
9	Light: Reflection	Laws of reflection; plane mirrors; spherical mirrors (concave and convex)
10	Light: Refraction	Laws of refraction; refractive index; prisms; dispersion of light

Topic 1: Heat and Temperature – Summary

🔑 Key Points:

Heat: Energy transferred due to temperature difference (Joules).
Temperature: Measure of average kinetic energy of particles (Kelvin, Celsius, Fahrenheit).
Temperature Scales: Celsius (°C), Fahrenheit (°F), Kelvin (K).
Conversions: K = °C + 273; °F = (9/5)°C + 32
Thermometers: Mercury, alcohol, thermocouple, resistance, infrared.

Topic 2: Thermal Expansion – Summary

🔑 Key Points:

Linear Expansion: ΔL = αL₀ΔT
Area Expansion: ΔA = βA₀ΔT (β ≈ 2α)
Volume Expansion: ΔV = γV₀ΔT (γ ≈ 3α)
Bimetallic Strips: Two metals with different expansion coefficients bend when heated (used in thermostats).
Applications: Rivets, expansion joints, thermostats.

Topic 3: Thermal Conductivity – Summary

🔑 Key Points:

Conductors: Allow heat to flow easily (e.g., metals like copper, aluminium).
Insulators: Resist heat flow (e.g., wood, rubber, air).
Factors affecting conductivity: Material type, temperature difference, cross-sectional area, length.
Thermal Conductivity (k): Q/t = kA(ΔT)/L

Topic 4: Gas Laws – Summary

🔑 Key Points:

Boyle's Law: P₁V₁ = P₂V₂ (at constant T)
Charles' Law: V₁/T₁ = V₂/T₂ (at constant P)
Pressure Law: P₁/T₁ = P₂/T₂ (at constant V)
General Gas Equation: P₁V₁/T₁ = P₂V₂/T₂
Ideal Gas Equation: PV = nRT

Topic 5: Evaporation and Boiling – Summary

🔑 Key Points:

Evaporation: Surface phenomenon, occurs at any temperature, cooling effect.
Boiling: Bulk phenomenon, occurs at a specific temperature (boiling point).
Factors affecting evaporation: Temperature, surface area, humidity, wind speed.
Latent Heat: Heat required for phase change without temperature change.
Specific Latent Heat of Fusion: L_f; Vaporization: L_v

Topic 6: Structure of Matter – Summary

🔑 Key Points:

Atomic Structure: Nucleus (protons + neutrons) + electrons.
Kinetic Theory: Particles in constant random motion.
States of Matter: Solid (fixed shape), Liquid (flow), Gas (fill container).
Brownian Motion: Random motion of particles in a fluid due to collisions.

Topic 7: Work, Energy and Power – Summary

🔑 Key Points:

Work: W = F × d × cos θ (Joules).
Energy: Capacity to do work. Forms: Kinetic, Potential, Thermal, Chemical, etc.
Conservation of Energy: Energy cannot be created or destroyed, only converted.
Power: P = W/t = F × v (Watts).
Kinetic Energy: E_k = ½mv²
Potential Energy: E_p = mgh

Topic 8: Simple Machines – Summary

🔑 Key Points:

Mechanical Advantage (MA): Load / Effort
Velocity Ratio (VR): Distance moved by effort / Distance moved by load
Efficiency: η = (MA/VR) × 100%
Levers: First, second, third class.
Pulleys: MA = number of rope segments supporting load.
Inclined Plane: MA = length/height

Topic 9: Reflection of Light – Summary

🔑 Key Points:

Laws of Reflection: (1) Angle of incidence = angle of reflection. (2) Incident ray, reflected ray, normal lie in the same plane.
Plane Mirror: Image is virtual, same size, laterally inverted.
Concave Mirror: Converging; used in telescopes, shaving mirrors.
Convex Mirror: Diverging; used in car side mirrors, security mirrors.
Mirror Formula: 1/f = 1/u + 1/v

Topic 10: Refraction of Light – Summary

🔑 Key Points:

Laws of Refraction: Snell's Law: n₁ sin θ₁ = n₂ sin θ₂
Refractive Index: n = c/v = sin i / sin r
Prisms: Dispersion of white light into spectrum (VIBGYOR).
Total Internal Reflection: Occurs when angle of incidence > critical angle.

Key Formulas Summary

Topic	Formula	Variables
Temperature Conversion	K = °C + 273	K = Kelvin, °C = Celsius
Linear Expansion	ΔL = αL₀ΔT	α = coefficient of linear expansion
Thermal Conductivity	Q/t = kA(ΔT)/L	k = thermal conductivity
Boyle's Law	P₁V₁ = P₂V₂	P = pressure, V = volume
General Gas Equation	P₁V₁/T₁ = P₂V₂/T₂	T = temperature (K)
Work	W = F × d × cos θ	F = force, d = distance
Kinetic Energy	E_k = ½mv²	m = mass, v = velocity
Potential Energy	E_p = mgh	g = 9.8 m/s², h = height
Power	P = W/t	W = work, t = time
Mirror Formula	1/f = 1/u + 1/v	f = focal length, u = object distance
Snell's Law	n₁ sin θ₁ = n₂ sin θ₂	n = refractive index

Revision Questions

Test your understanding of all First Term topics:

Section A: Multiple Choice (Choose the correct option)

The SI unit of temperature is:
A) Celsius B) Fahrenheit C) Kelvin D) Joule
Boyle's Law states that at constant temperature:
A) P ∝ V B) P ∝ 1/V C) V ∝ T D) P ∝ T
The energy possessed by a moving object is called:
A) Potential energy B) Kinetic energy C) Thermal energy D) Chemical energy
Which of the following is a good conductor of heat?
A) Wood B) Rubber C) Copper D) Plastic
The angle of incidence is equal to the angle of reflection according to:
A) Snell's Law B) Law of Reflection C) Boyle's Law D) Charles' Law

Answers: 1-C, 2-B, 3-B, 4-C, 5-B

Section B: Short Answer Questions

Distinguish between heat and temperature.
State the three gas laws and write their mathematical expressions.
Explain the difference between evaporation and boiling.
State the law of conservation of energy.
Define refractive index and write its formula.

Section C: Calculation Questions

A metal rod of length 2.0 m increases by 0.002 m when heated from 20°C to 100°C. Calculate the coefficient of linear expansion.
A gas occupies 500 cm³ at 1 atm pressure. What volume will it occupy at 2.5 atm at constant temperature?
A 5 kg object is lifted to a height of 10 m. Calculate its potential energy. (g = 10 m/s²)
A simple machine has a mechanical advantage of 4 and a velocity ratio of 5. Calculate its efficiency.
An object is placed 15 cm in front of a concave mirror with focal length 10 cm. Calculate the image distance.

Answers to Section B

1. Heat is energy transferred due to temperature difference; temperature is the measure of average kinetic energy of particles.

2. Boyle's: P₁V₁ = P₂V₂; Charles': V₁/T₁ = V₂/T₂; Pressure: P₁/T₁ = P₂/T₂

3. Evaporation occurs at any temperature on the surface; boiling occurs at a specific temperature throughout the liquid.

4. Energy cannot be created or destroyed, only converted from one form to another.

5. n = c/v = sin i / sin r

Answers to Section C

1. α = ΔL/(L₀ΔT) = 0.002/(2.0 × 80) = 1.25 × 10⁻⁵ /°C

2. V₂ = P₁V₁/P₂ = 1 × 500/2.5 = 200 cm³

3. E_p = mgh = 5 × 10 × 10 = 500 J

4. η = (MA/VR) × 100% = (4/5) × 100 = 80%

5. 1/f = 1/u + 1/v → 1/10 = 1/15 + 1/v → v = 30 cm

Examination Preparation Tips

📌 Tips for Success:

Review all formulas – make a formula sheet and memorise them.
Understand key definitions – be able to explain concepts in your own words.
Practice calculations – work through all examples and assignment questions.
Draw diagrams – practice drawing ray diagrams, mirror diagrams, and machine diagrams.
Know your units – be familiar with SI units for all quantities.
Time management – allocate time for each section during the exam.
Read questions carefully – identify what is being asked before answering.

Board Summary

╔════════════════════════════════════════════════════════════════════════════╗ ║ SS2 PHYSICS – FIRST TERM REVISION ║ ╠════════════════════════════════════════════════════════════════════════════╣ ║ ║ ║ WEEK 1: HEAT & TEMPERATURE ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Heat: Energy transfer; Temperature: average KE ║ ║ • Scales: K = °C + 273 ║ ║ ║ ║ WEEK 2: THERMAL EXPANSION ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • ΔL = αL₀ΔT, ΔA = βA₀ΔT, ΔV = γV₀ΔT ║ ║ ║ ║ WEEK 3: THERMAL CONDUCTIVITY ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Q/t = kA(ΔT)/L; Conductors vs Insulators ║ ║ ║ ║ WEEK 4: GAS LAWS ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Boyle: P₁V₁ = P₂V₂; Charles: V₁/T₁ = V₂/T₂ ║ ║ • Pressure: P₁/T₁ = P₂/T₂; General: P₁V₁/T₁ = P₂V₂/T₂ ║ ║ ║ ║ WEEK 5: EVAPORATION & BOILING ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Evaporation: surface, any temperature ║ ║ • Boiling: bulk, fixed temperature ║ ║ ║ ║ WEEK 6: STRUCTURE OF MATTER ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Atom: nucleus + electrons; Kinetic Theory; Brownian motion ║ ║ ║ ║ WEEK 7: WORK, ENERGY & POWER ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • W = Fd, Eₖ = ½mv², Eₚ = mgh, P = W/t ║ ║ ║ ║ WEEK 8: SIMPLE MACHINES ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • MA = Load/Effort; VR = distance ratio; η = (MA/VR) × 100% ║ ║ ║ ║ WEEK 9: REFLECTION ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • i = r; 1/f = 1/u + 1/v; Concave (converging), Convex (diverging) ║ ║ ║ ║ WEEK 10: REFRACTION ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ • Snell: n₁ sin θ₁ = n₂ sin θ₂; n = c/v = sin i/sin r ║ ║ ║ ╚════════════════════════════════════════════════════════════════════════════╝

✅ Good luck with your examination!

Remember to stay calm, read all questions carefully, and show your working clearly. You've got this! 💪